Merge branch 'virtio' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

* 'virtio' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  virtio_blk: Remove VBID ioctl
  virtio_blk: Add 'serial' attribute to virtio-blk devices (v2)
  virtio_blk: support barriers without FLUSH feature